Electromagnetic pulse welding of micro joints between metal sheets

Abstract

The present application relates to the connection method of micro-welding point between metal plates, and particularly relates to an electromagnetic pulse welding method of micro-welding point between metal plates, comprising the following steps: S1, surface treatment is carried out on the surface of two metal plates to remove surface impurities; one metal plate is used as a base plate, and the other metal plate is used as a flying plate; S2, an insulating layer is connected on the surface of the base plate, and a groove is obtained by machining, and a through hole is arranged at the corresponding position of the insulating layer and the groove; S3, tin-copper alloy blank is machined to obtain a sheet-shaped tin-copper alloy piece and a columnar tin-copper alloy piece; the sheet-shaped tin-copper alloy piece is fixed at the bottom end of the groove, and the columnar tin-copper alloy piece is fixed on the surface of the flying plate; S4, the base plate and the flying plate are arranged oppositely, the groove on the base plate corresponds to the position of the columnar tin-copper alloy piece on the flying plate, and electromagnetic pulse welding is carried out on the tin-copper alloy between the metal plates to obtain the micro-welding point between the metal plates. The operation is simple, and the bonding strength and conductivity of the micro-welding point between the metal plates can be effectively improved.

Description

Technical Field

[0001] This invention relates to a method for connecting micro-solder joints between metal plates, and more specifically to an electromagnetic pulse welding method for micro-solder joints between metal plates. Background Technology

[0002] Currently, there are three main welding methods commonly used both domestically and internationally: fusion welding, semi-solid welding, and solid welding. When considering welding metal plates, each of these three methods has its advantages in terms of welding quality, efficiency, and cost.

[0003] With the rapid development of science and technology, metal electronic devices are increasingly miniaturized and thin-walled, leading to ever-increasing performance requirements for inter-board micro-soldering joints. Due to the narrow inter-board distances, conventional fusion welding (such as arc welding) and semi-solid welding (such as soldering) methods cannot accurately penetrate the solder joints, hindering their widespread application. Other advanced welding technologies (such as laser welding) are also unsuitable for general electronic device production due to their high cost. Against this backdrop, electromagnetic pulse welding (EMW) has become widely used for welding similar or dissimilar metals due to its advantages of simple operation, safety, speed, and wide applicability. Furthermore, the instantaneous high temperature and high pressure characteristics of EMW are particularly suitable for joining low-melting-point metals between metal plates. However, a drawback is that during EMW welding, the fly plate undergoes severe localized plastic deformation under the strong electromagnetic force, affecting the connection state of the micro-soldering joints and reducing their bonding strength and conductivity. Summary of the Invention

[0004] The purpose of this invention is to provide an electromagnetic pulse welding method for micro-welds between metal plates, which is simple to operate and can effectively improve the bonding strength and conductivity of micro-welds between metal plates.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An electromagnetic pulse welding method for micro-solder joints between metal plates includes the following steps: S1. Surface treatment is performed on the surfaces of the two metal plates to remove surface impurities; one metal plate is used as the substrate and the other metal plate is used as the flyboard. S2, an insulating layer is connected to one side surface of the substrate and a groove is machined thereon, and the insulating layer is provided with through holes at the corresponding positions of the groove; S3, the tin-copper alloy blank is machined to obtain sheet-shaped tin-copper alloy parts and columnar tin-copper alloy parts; the sheet-shaped tin-copper alloy parts are fixed to the bottom end of the groove on the substrate surface, and the columnar tin-copper alloy parts are fixed to the surface of the flyboard. S4. The substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates to prepare micro solder joints between the metal plates.

[0006] In some embodiments, the two metal plates in S1 are independently made of aluminum, copper, silver, magnesium, iron, titanium, lithium metal or alloy. The thickness of the two metal plates in S1 is independently 0.5~1mm.

[0007] In some embodiments, the surface treatment in S1 includes grinding, polishing, and cleaning with anhydrous ethanol.

[0008] In some embodiments, the insulating layer in S2 is made of polyethylene and its composite materials, polypropylene and its composite materials, or nylon and its composite materials; the thickness of the insulating layer in S2 is 0.1~0.5mm, and the diameter of the through holes on the insulating layer is 0.5~5mm.

[0009] In some embodiments, the sheet-like tin-copper alloy part in S3 is in the shape of a disc with a diameter of 0.5~5mm and a thickness of 0.1~0.5mm; The columnar tin-copper alloy component in S3 is cylindrical with a diameter of 0.5~5mm and a height of 0.1~1mm.

[0010] In some embodiments, the groove in S3 is cylindrical with an inner diameter of 0.5~5mm, and the inner diameter of the groove is greater than or equal to the diameter of the sheet tin-copper alloy part. The groove depth is 0.1~1mm, and the groove depth is greater than or equal to the thickness of the sheet tin-copper alloy part.

[0011] In some embodiments, the diameter of the columnar tin-copper alloy component in S3 is less than or equal to the diameter of the through hole on the insulating layer in S2; The diameter of the columnar tin-copper alloy part in S3 is less than or equal to the diameter of the sheet-like tin-copper alloy part; The diameter of the sheet-like tin-copper alloy piece in S3 is less than or equal to the inner diameter of the groove in the substrate; The diameter of the through hole on the insulating layer in S2 is less than or equal to the inner diameter of the groove on the substrate in S3.

[0012] In some embodiments, the height A of the columnar tin-copper alloy component in S3 is greater than or equal to B + (CD), where B is the thickness of the insulating layer, C is the depth of the groove, and D is the thickness of the sheet-like tin-copper alloy component.

[0013] In some embodiments, in step S3, the sheet-like tin-copper alloy component is fixed to the bottom end of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0014] In some embodiments, the discharge voltage for electromagnetic pulse welding in S4 is set to 10~25kV; the initial gap between the sheet-like tin-copper alloy parts and the columnar tin-copper alloy parts between the metal plates in S4 is set to 0.5~2mm.

[0015] The beneficial effects of this invention are: 1. The present invention connects an insulating layer to one side surface of a substrate and machines a groove thereon. The insulating layer has through holes at positions corresponding to the groove. During electromagnetic pulse welding, the insulating layer can prevent the substrate from contacting the fly plate and improve the conductivity of the micro-solder joints between the metal plates.

[0016] 2. Electromagnetic pulse welding relies on the instantaneous discharge of capacitor banks and the coupling effect of induced eddy currents to generate a strong electromagnetic force on the workpiece, driving collisions and causing shear plastic deformation and jet formation on the workpiece surface to bond the metal. Therefore, electromagnetic pulse welding does not have special requirements for the melting point and crystal structure of the workpiece. During electromagnetic pulse welding, interface collisions include head-on collisions and oblique collisions, with oblique collisions being a key factor in generating jets and effectively improving interface bonding strength. For micro-solder joints required for metal electronic devices, this metal jet can affect the service environment of surrounding solder joints. In this application, it is specified that "the diameter of the columnar tin-copper alloy part is less than or equal to the diameter of the through hole on the insulating layer; the diameter of the columnar tin-copper alloy part is less than or equal to the diameter of the sheet-like tin-copper alloy part; the diameter of the sheet-like tin-copper alloy part is less than or equal to the inner diameter of the groove on the substrate; the diameter of the through hole on the insulating layer is less than or equal to the inner diameter of the groove on the substrate," in order to control the range of the jet within the groove on the substrate or the through hole on the insulating layer, minimizing the adverse effects of the jet. The height of the columnar tin-copper alloy component is specified as "A≥B+(CD), where B is the thickness of the insulating layer, C is the depth of the groove, and D is the thickness of the sheet tin-copper alloy component". This ensures that when the columnar tin-copper alloy component on the flyboard collides with the sheet tin-copper alloy component on the substrate, it can undergo lateral deformation, forming an expansion effect in the groove of the substrate, thereby improving the bonding strength of the micro-solder joints between the metal plates. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the inter-metal plate micro-weld joints before electromagnetic pulse welding in an embodiment of this application; Figure 2 This is a schematic diagram of electromagnetic pulse welding of micro-weld points between metal plates in an embodiment of this application.

[0018] In the figure, 1—substrate, 11—groove, 2—flying plate, 3—insulating layer, 31—through hole, 4—sheet-shaped tin-copper alloy component, 5—column-shaped tin-copper alloy component, 6—pad, 7—energized coil. Detailed Implementation

[0019] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0020] Currently, during electromagnetic pulse welding, the fly plate undergoes severe localized plastic deformation under the strong electromagnetic force, affecting the connection state of the micro-weld joints between metal plates and reducing the bonding strength and conductivity of the micro-weld joints. Based on this, this application provides an electromagnetic pulse welding method for micro-weld joints between metal plates, comprising the following steps: S1, perform surface treatment on the surfaces of the two metal plates to remove surface impurities; use one metal plate as the substrate 1 and the other metal plate as the flyboard 2.

[0021] S2, see S2. Figure 1 As shown, an insulating layer 3 is connected to one side surface of the substrate 1 and a groove 11 is machined thereon. The insulating layer 3 has a through hole 31 at the corresponding position of the groove 11.

[0022] S3, the tin-copper alloy blank is machined to obtain a sheet-shaped tin-copper alloy part 4 and a columnar tin-copper alloy part 5. The sheet-shaped tin-copper alloy part 4 is fixed to the bottom end of the groove 11 on the surface of the substrate 1, and the columnar tin-copper alloy part 5 is fixed to the surface of the flyboard 2.

[0023] S4, the substrate 1 and the flyboard 2 are arranged opposite each other, with the groove 11 on the substrate 1 corresponding to the columnar tin-copper alloy part 5 on the flyboard 2. A spacer 6 is used to separate the substrate 1 and the flyboard 2. Electromagnetic pulse welding is then performed on the tin-copper alloy between the metal plates. (See also...) Figure 2 As shown, the energized coil 7 generates a magnetic field. Under the action of electromagnetic force, the flyer plate 2 gains kinetic energy and collides with the substrate 1. This causes the columnar tin-copper alloy component 5 to collide with the sheet-like tin-copper alloy component 4 in the groove 11 of the substrate 1. This causes shear plastic deformation at the collision interface, accompanied by interfacial jetting, thereby achieving a firm connection between the sheet-like tin-copper alloy component 4 and the columnar tin-copper alloy component 5, thus preparing a micro-solder joint between the metal plates. Furthermore, the insulating layer 3 avoids direct contact between the substrate 1 and the flyer plate 2, improving the conductivity of the micro-solder joint between the metal plates.

[0024] Specific examples include: Example 1: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.5mm thick copper plates to remove surface impurities and oil. One copper plate serves as the substrate, and the other as the flyboard.

[0025] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0026] The insulation layer has a thickness of 0.1 mm and a through hole diameter of 0.5 mm; the groove is cylindrical with an inner diameter of 0.5 mm and a depth of 0.1 mm.

[0027] For example, the insulating layer is made of polyethylene.

[0028] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0029] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0030] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 0.5 mm and a thickness of 0.1 mm.

[0031] The columnar tin-copper alloy part is cylindrical with a diameter of 0.5 mm and a height of 0.1 mm.

[0032] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0033] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 10kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 0.5mm.

[0034] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0035] Example 2: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.8mm thick copper plates to remove surface impurities and oil. One copper plate serves as the substrate, and the other as the flyboard.

[0036] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0037] The insulation layer has a thickness of 0.3 mm and a through hole diameter of 2.5 mm; the groove is cylindrical with an inner diameter of 2.5 mm and a depth of 0.5 mm.

[0038] For example, the insulating layer is made of polyethylene.

[0039] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0040] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0041] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 2.5 mm and a thickness of 0.3 mm.

[0042] The columnar tin-copper alloy part is cylindrical with a diameter of 2.5 mm and a height of 0.5 mm.

[0043] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0044] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 15kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 1.0mm.

[0045] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0046] Example 3: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 1.0mm thick copper plates to remove surface impurities and oil. One copper plate serves as the substrate, and the other as the flyboard.

[0047] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0048] The insulation layer has a thickness of 0.5 mm and a through hole diameter of 5.0 mm; the groove is cylindrical with an inner diameter of 5.0 mm and a depth of 1.0 mm.

[0049] For example, the insulating layer is made of polyethylene.

[0050] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0051] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0052] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 5.0 mm and a thickness of 0.5 mm.

[0053] The columnar tin-copper alloy part is cylindrical with a diameter of 5.0 mm and a height of 1.0 mm.

[0054] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0055] S4. The substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 18kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 2.0mm.

[0056] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0057] Example 4: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.8mm thick aluminum and copper plates to remove surface impurities and oil. The aluminum plate serves as the substrate, and the copper plate as the flyboard.

[0058] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0059] The insulation layer has a thickness of 0.3 mm and a through hole diameter of 2.5 mm; the groove is cylindrical with an inner diameter of 2.5 mm and a depth of 0.5 mm.

[0060] For example, the insulating layer is made of polyethylene.

[0061] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0062] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0063] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 2.5 mm and a thickness of 0.3 mm.

[0064] The columnar tin-copper alloy part is cylindrical with a diameter of 2.5 mm and a height of 0.5 mm.

[0065] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0066] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 15kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 1.0mm.

[0067] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0068] Example 5: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.8mm thick steel and copper plates to remove surface impurities and oil. The steel plate serves as the base plate, and the copper plate as the flyboard.

[0069] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0070] The insulation layer has a thickness of 0.3 mm and a through hole diameter of 2.5 mm; the groove is cylindrical with an inner diameter of 2.5 mm and a depth of 0.5 mm.

[0071] For example, the insulating layer is made of polyethylene.

[0072] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0073] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0074] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 2.5 mm and a thickness of 0.3 mm.

[0075] The columnar tin-copper alloy part is cylindrical with a diameter of 2.5 mm and a height of 0.5 mm.

[0076] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0077] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 16kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 1.0mm.

[0078] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0079] Example 6: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.8mm thick copper and steel plates to remove surface impurities and oil. The copper plate serves as the substrate, and the steel plate as the flyboard.

[0080] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0081] The insulation layer has a thickness of 0.3 mm and a through hole diameter of 2.5 mm; the groove is cylindrical with an inner diameter of 2.5 mm and a depth of 0.5 mm.

[0082] For example, the insulating layer is made of polyethylene.

[0083] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0084] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0085] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 2.5 mm and a thickness of 0.3 mm.

[0086] The columnar tin-copper alloy part is cylindrical with a diameter of 2.5 mm and a height of 0.5 mm.

[0087] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0088] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 19kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 1.0mm.

[0089] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0090] Example 7: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.8mm thick copper and titanium plates to remove surface impurities and oil. The copper plate serves as the substrate, and the titanium plate as the flyboard.

[0091] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0092] The insulation layer has a thickness of 0.3 mm and a through hole diameter of 2.5 mm; the groove is cylindrical with an inner diameter of 2.5 mm and a depth of 0.5 mm.

[0093] For example, the insulating layer is made of polyethylene.

[0094] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0095] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0096] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 2.5 mm and a thickness of 0.3 mm.

[0097] The columnar tin-copper alloy part is cylindrical with a diameter of 2.5 mm and a height of 0.5 mm.

[0098] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0099] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 21kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 1.0mm.

[0100] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0101] Example 8: An electromagnetic pulse welding method for micro-solder joints between metal plates, comprising the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 1.0mm thick copper and titanium plates to remove surface impurities and oil. The copper plate serves as the substrate, and the titanium plate as the flyboard.

[0102] S2, an insulating layer is bonded to one side of the substrate and a groove is machined thereon. The insulating layer has through holes at the positions corresponding to the groove.

[0103] The insulation layer has a thickness of 0.5 mm and a through hole diameter of 5.0 mm; the groove is cylindrical with an inner diameter of 5.0 mm and a depth of 1.0 mm.

[0104] For example, the insulating layer is made of polyethylene.

[0105] It should also be noted that there is no specific order for bonding the insulating layer and machining the groove; that is, the insulating layer can be bonded first, and then the groove can be machined, or the groove can be machined first, and then the insulating layer can be bonded.

[0106] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0107] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 5.0 mm and a thickness of 0.5 mm.

[0108] The columnar tin-copper alloy part is cylindrical with a diameter of 5.0 mm and a height of 1.0 mm.

[0109] The sheet-shaped tin-copper alloy component is fixed to the bottom of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

[0110] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 25kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 2.0mm.

[0111] The specific process of electromagnetic pulse welding is as follows: a magnetic field is generated by an energized coil. Under the action of electromagnetic force, the flying plate gains kinetic energy and crashes into the substrate, which drives the columnar tin-copper alloy component to crash into the sheet tin-copper alloy component in the groove of the substrate. This causes shear plastic deformation at the collision interface, accompanied by interface jet, thereby achieving a firm connection between the sheet tin-copper alloy component and the columnar tin-copper alloy component, and preparing micro-weld joints between metal plates.

[0112] In Comparative Example 1, unlike Example 1, after the substrate and the flyboard are arranged opposite each other, the tin-copper alloy between the metal plates is arc welded.

[0113] In Comparative Example 2, unlike Example 2, the tin-copper alloy between the metal plates is arc welded after the substrate and the flyboard are arranged opposite each other.

[0114] In Comparative Example 3, unlike Example 3, the tin-copper alloy between the metal plates is arc welded after the substrate and the flyboard are arranged opposite each other.

[0115] Comparative Example 4: An electromagnetic pulse welding method for micro-solder joints between metal plates, without an insulating layer, specifically includes the following steps: S1 involves grinding, polishing, and cleaning with anhydrous ethanol on the surfaces of two 0.8mm thick copper plates to remove surface impurities and oil. One copper plate serves as the substrate, and the other as the flyboard.

[0116] S2, A groove is machined on one side of the substrate. The groove is cylindrical with an inner diameter of 2.5 mm and a depth of 0.5 mm.

[0117] S3, the tin-copper alloy blank is machined to obtain sheet-like tin-copper alloy parts and columnar tin-copper alloy parts.

[0118] The sheet-like tin-copper alloy part is in the shape of a disc, with a diameter of 2.5 mm and a thickness of 0.3 mm.

[0119] The columnar tin-copper alloy part is cylindrical with a diameter of 2.5 mm and a height of 0.5 mm.

[0120] Sheet-shaped tin-copper alloy parts are fixed to the bottom of the groove on the substrate surface by brazing, and columnar tin-copper alloy parts are fixed to the surface of the flyboard by brazing.

[0121] S4, the substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. The substrate and the flyboard are separated by a spacer. Electromagnetic pulse welding is performed on the tin-copper alloy between the metal plates. The discharge voltage of the electromagnetic pulse welding is set to 15kV. The initial gap S between the sheet tin-copper alloy part and the columnar tin-copper alloy part is set to 1.0mm.

[0122] Comparing Comparative Examples 1-3 with Examples 1-3, it was found that due to the small initial gap S, Arc welding was difficult to perform in Comparative Examples 1-3 because the welding rod could not accurately enter the weld point between the plates. Examples 1-3, however, could prepare micro-welds between metal plates using electromagnetic pulse welding. Furthermore, while Comparative Example 4 could prepare micro-welds between metal plates using electromagnetic pulse welding, the lack of insulating material between the substrate and the flyer meant that contact could not be guaranteed during collisions due to localized shear plastic deformation or jetting. Example 2, based on Comparative Example 4, added an insulating material between the substrate and the flyer, effectively preventing contact between them and improving the conductivity of the micro-welds between the metal plates.

[0123] Electromagnetic pulse welding (EMB) relies on the instantaneous discharge of capacitor banks and the coupling effect of induced eddy currents to generate a strong electromagnetic force on the workpiece, driving collisions and causing shear plastic deformation and jet formation on the workpiece surface to bond the metal. Therefore, EMB welding does not have special requirements for the melting point or crystal structure of the workpiece. During EMB welding, interface collisions include direct and oblique collisions, with oblique collisions being a key factor in generating jets and effectively improving interface bonding strength. For micro-solder joints required in metal electronic devices, this metal jet can affect the service environment of surrounding solder joints. In this application, it is specified that "the diameter of the columnar tin-copper alloy part is less than or equal to the diameter of the through-hole on the insulating layer; the diameter of the columnar tin-copper alloy part is less than or equal to the diameter of the sheet-like tin-copper alloy part; the diameter of the sheet-like tin-copper alloy part is less than or equal to the inner diameter of the groove on the substrate; and the diameter of the through-hole on the insulating layer is less than or equal to the inner diameter of the groove on the substrate," in order to control the jet range within the groove on the substrate or the through-hole on the insulating layer, minimizing the adverse effects of the jet. The requirement that "the height A of the columnar tin-copper alloy component is greater than or equal to B + (CD), where B is the thickness of the insulating layer, C is the groove depth, and D is the thickness of the sheet-like tin-copper alloy component" ensures that the columnar tin-copper alloy component on the flyboard can undergo lateral deformation when it collides with the sheet-like tin-copper alloy component on the substrate. This creates an expansion effect within the groove of the substrate, improving the bonding strength of the micro-solder joints between the metal plates. By bonding an insulating layer to the substrate surface, contact between the substrate and the flyboard can be avoided, improving the conductivity of the micro-solder joints between the metal plates.

[0124] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. An electromagnetic pulse welding method for micro-solder joints between metal plates, characterized in that, Includes the following steps: S1. Surface treatment is performed on the surfaces of the two metal plates to remove surface impurities; one metal plate is used as the substrate and the other metal plate is used as the flyboard. S2, an insulating layer is connected to one side of the substrate, and a groove is machined on the same side of the substrate. The insulating layer has through holes at positions corresponding to the groove. S3, the tin-copper alloy blank is machined to obtain sheet-shaped tin-copper alloy parts and columnar tin-copper alloy parts; the sheet-shaped tin-copper alloy parts are fixed to the bottom end of the groove on the substrate surface, and the columnar tin-copper alloy parts are fixed to the surface of the flyboard. S4. The substrate and the flyboard are arranged opposite each other, and the groove on the substrate corresponds to the position of the columnar tin-copper alloy part on the flyboard. Electromagnetic pulse welding is performed on the sheet-like tin-copper alloy part and the columnar tin-copper alloy part between the metal plates to prepare micro-weld joints between the metal plates.

2. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 1, characterized in that: The two metal plates in S1 are made of aluminum, copper, silver, magnesium, iron, titanium, lithium metal or alloy. The thickness of the two metal plates in S1 is independently 0.5~1mm.

3. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 1, characterized in that: The surface treatment in S1 includes grinding, polishing, and cleaning with anhydrous ethanol.

4. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 1, characterized in that: The insulating layer in S2 is made of one of the following materials: polyethylene, polyethylene composite material, polypropylene, polypropylene composite material, nylon, and nylon composite material. The thickness of the insulating layer in S2 is 0.1~0.5mm, and the diameter of the through hole on the insulating layer is 0.5~5mm.

5. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 1, characterized in that: The sheet-like tin-copper alloy part in S3 is in the shape of a disc, with a diameter of 0.5~5mm and a thickness of 0.1~0.5mm; The columnar tin-copper alloy component in S3 is cylindrical with a diameter of 0.5~5mm and a height of 0.1~1mm.

6. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 5, characterized in that: The groove in S3 is cylindrical with an inner diameter of 0.5~5mm, and the inner diameter of the groove is greater than or equal to the diameter of the sheet tin-copper alloy part. The groove depth is 0.1~1mm, and the groove depth is greater than or equal to the thickness of the sheet tin-copper alloy part.

7. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 5, characterized in that: The diameter of the columnar tin-copper alloy component in S3 is less than or equal to the diameter of the through hole on the insulating layer in S2. The diameter of the columnar tin-copper alloy part in S3 is less than or equal to the diameter of the sheet-like tin-copper alloy part; The diameter of the sheet-like tin-copper alloy piece in S3 is less than or equal to the inner diameter of the groove in the substrate; The diameter of the through hole on the insulating layer in S2 is less than or equal to the inner diameter of the groove on the substrate in S3.

8. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 5, characterized in that: In S3, the height A of the columnar tin-copper alloy component is greater than or equal to B + (C - D), where B is the thickness of the insulating layer, C is the depth of the groove, and D is the thickness of the sheet-like tin-copper alloy component.

9. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 1, characterized in that: In step S3, the sheet-shaped tin-copper alloy component is fixed to the bottom end of the groove on the substrate surface by brazing, and the columnar tin-copper alloy component is fixed to the surface of the flyboard by brazing.

10. The electromagnetic pulse welding method for inter-plate micro-weld joints according to claim 1, characterized in that, The discharge voltage for electromagnetic pulse welding in S4 is set to 10~25kV; In S4, the initial gap between the sheet-like tin-copper alloy component and the columnar tin-copper alloy component between the metal plates is set to 0.5~2mm.

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